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In organometallic chemistry, the activation of cyclopropanes by transition metals is a research theme with implications for organic synthesis and homogeneous catalysis. [1] Being highly strained, cyclopropanes are prone to oxidative addition to transition metal complexes. The resulting metallacycles are susceptible to a variety of reactions ...
Vanadium(V) oxide (in the contact process), finely divided iron (in the Haber process), and nickel (in catalytic hydrogenation) are some of the examples. Catalysts at a solid surface (nanomaterial-based catalysts) involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals ...
There are various types of pincer ligands that are used in transition metal catalysis. Often, they have the same two-electron donor flanking the metal centre, but this is not a requirement. Examples of transition metal pincer complexes. The most common pincer ligand designs are PCP, NCN, PCN, SCS, and PNO.
Examples of an industrially useful hydrides are HCo(CO) 4 and HRh(CO)(PPh 3) 3, which are catalysts for hydroformylation. HFeCl(dppe) 2 is one of the most accessible transition metal hydrides. The first molecular hydrides of the transition metals were first reported in the 1930s by Walter Hieber and coworkers.
However, there are transition metal photoredox catalysts that exist without a counter-ion such as tris(2-phenylpyridine)iridium (often abbreviated Ir(ppy) 3). The significance of these counter-ions are dependent on the ion association between the photoredox catalyst and its counter-ion(s) and is dependent on the solvent used for the reaction.
Catalyst prepared and handled under anaerobic condition reverses the selectivity to favor the secondary boronate ester. What has been debated is the coordination of the alkene. In the dissociative mechanism, proposed by Männig and Nöth, [ 4 ] and supported by Evans and Fu [ 5 ] the coordination is accompanied by the loss of one ...
Transition metal oxides are compounds composed of oxygen atoms bound to transition metals. They are commonly utilized for their catalytic activity and semiconducting properties. Transition metal oxides are also frequently used as pigments in paints and plastics, most notably titanium dioxide. Transition metal oxides have a wide variety of ...
Various transition metal complexes, namely those of Cu, Fe, Ru, Ni, and Os, have been employed as catalysts for ATRP. In an ATRP process, the dormant species is activated by the transition metal complex to generate radicals via one electron transfer process. Simultaneously the transition metal is oxidized to higher oxidation state.